The present invention relates to a new type of pin tumbler lock and is particularly characterized by the unusual operating features of being pick-proof and key changeable. That is, the keying of the lock may be changed simply by inserting the new key under specified conditions. No lock disassembly is required.
Conventional pin tumbler locks can be picked because the pins may be aligned one at a time in a serial fashion, although the intention is that all pins must be aligned simultaneously to open the lock.
It is an important object of the invention to provide a pick-proof lock.
It is a further object of the invention to provide user key change capability without disassembly consistent with the preceding object.
It is a further object of the invention that serial pin setting cannot be accomplished consistent with one or both of the preceding objects.